Namastey, I want to know that is chanting Lord Shiva's Mantra i.e Om Namah Shivaya mantra for 40 days effective? ~Hari Om
well chanting aum namah shivaya is always beneficial be it for one day or 40 day...the more you chant , the more it purifies you and benefits you.
But as per this source: http://www.rudraksha-ratna.com/40-day-practice_467.html5 the period of 40 days is considered auspicious. This source also states the importance of chanting Mantra with the help of Rudraksha Mala. Do you agree with the fact? ~Hari Om
With diksha, it is a lifetime vow, not 40 days. Of course the initiated devotee can intensify the practise for certain periods, like 40 days ... instead of doing one round per day, do 10 a day for 40 days ... something like that.